Hectograph blanket having an acidic bonding agent



Oct. 28, 1941. R, c, SOUR 2,260,506

HECTOGRAPH BLANKET'HAVING AN ACIDICBONDING AGENT Filed Jan. 8, 1940 g [XIX/X/XM/X Patented Oct. 28, 1941 UNITED STATES PATENT OFFICE HECTOGRAPH BLANKET HAYING AN I ACIDIC BONDING AGENT Robert C. Bour, Chicago, Ill., assignor to Ditto,

Incorporated, Chicago, 111.,

Virginia a corporation of Application January 8, 1940, Serial No. 312,929

(Cl. in-31.6)

- has tanning characteristics such as, for example,

linseed oil or other drying oils, or mixtures of cellulose esters and tanning agents such as alum,

phenol, resorcinol, formaldehyde, and the like. Such bonding compositions have the inherent disadvantage that they cause progressive tanning of the overlying hectograph copy mass,'with the result that after a period of time the hectograph copy mass becomes so hard that it is not com-- mercially usable. In some cases, non-tanning bonding compositions have been used, as for example the sulphonated castor oil disclosed'in Hoskins Patent 2,098,662. These sulphonated oil compositions, while. in general suitable, are difflcult to prepare and apply so as to obtain uniform results.

I have discoveredthat the non-tanning. carboxylic acids and non-tanning salts of carboxylic acids which dissociate in water or alcohol to form the corresponding acid are effective bonding agents when used .alone or in combination with other ingredients as theintermediate bonding film or layer of a hectograph blanket. Such acidic substances allow the production of hectograph blankets quickly and economically, and when used alone or in conjunction with other The invention is further illustrated in, conjunction with the accompanying drawing in which-- Fig. 1 is a sectional view of a hectograph blanket illustrating one embodiment of my invention,

and a Fig. 2 is a sectional view of a modified form of hectograph blanket embodying my invention. Referring to the drawing, and particularly to Fig. 1 in which 'a preferred embodiment of the invention is illustrated, the reference character I is a gelatinous copy mass secured by means of a him or layer 2 comprising an acidic substance to a'fiexible backing consisting of a paper, cloth non-tanning substances as the intermediate bond- .or'other fabric base 4 coated on both sides with a relatively non-adhesive lacquer 3 and 5. In the embodiment of the-invention shown in Fig. l, thebonding layer 2 preferably comprises one of the usual cellulose derivative lacquers containing an acidic substance having a hydrophobic long chain aliphatic radical attached to a hydrophilic carboxylic radical or dissociable salt thereof.

In the embodiment of the invention shown in Fig. 2, the hectograph blanket comprises a gelatinous copy mass l secured to a paper, fabric or similar backing 4 which is impregnated with an acidic substance alone or in admixture with other ingredients, preferably of a non-tanning and non-sulfonated character.

In the embodiment of the invention shown in both Fig. 1 and Fig. 2, the portion of -the backing remote from the copy mass is covered with lacquer or similar substance illustrated by the layer 5. This outer covering is not essential, but is preferable when the hectograph blanket is to be used in the form of a roll, in order to avoid excessive adherence of the backing to the hectograph copy mass.

naphthenic acids; sodium naphthenates, oleic acid, acetic acid, malic acid and lactic acid.

Preferred acidic substances are naphthenic acid, sodium naphthenates and erucic acid.

The acidic substances may be used alone, but

generally are admixed with other materials, preferably non-tanning and non-sulfonated ingredients. 1

' The preferred bonding composition is a coating composition comprising a cellulose ester such as cellulose acetate, or a nitrocellulose, a volatile solvent for the cellulose ester such as ethyl acetate andan acidic substance which is intimately mixed with the other ingredients.

-.To more clearly set forth the practice in accordance with the invention and to more specifically point out the nature of the product and process contemplated thereby, several specific, il-

lustrative examples are hereinafter set forth, it

being understood that these examples illustrate several embodiments which have given satisfactory results and are not intended to restrict the invention thereto.

Example I.A composition of lacquer.

sulted.

lulose lacquer containing 35% solids.

was coated on a cloth which had been sized with Conventional hectograph mass was heated to a temperature of 70 C. and then poured on top of the above coating, and allowed to remain melted for twenty minutes. After allowing sumcient time for the hectograph mass to set, an examination showed that the above com-' position had caused the hectograph mass to adhere or bond to the cloth.

Example II .-30% by weight of sodium naphthenate was dissolved in an air dry lacquer. This lacquer was coated on cloth by means of a doctor knife. Hectograph mass was applied to the cloth as in the previous example, and good bond re- Example NI parts of oleic acid were dissolved in 80 parts of a conventional nitrocel- This solution was applied ,to cotton cloth prep-coated Hectograph mass is obtained. The conditions are then suitable for the practice of this invention.

The term non-tanning acidic organic substances as used in this specification and claims,

Similar results were obtained with other acids andsalts thereof, in film forming solutions such as those stated above. For example, the following acidic substances were tried with positive result: sebacic acid, oleic acid, triethanol-' amine oleate, erucic acid, camphoric anhydride and crotonic anhydride. In fact, every acidic substance tried under. varying conditions proved to be, to some extent at least, suitable for the purposes. of this invention.

From the above examples, it is apparent that the ingredients, proportions and procedures may be. varied within wide limits without departing from the. spirit or scope of the invention. In evaluating thev probable influence 'of such varia- 5 tions on the quality of bond obtained, the following may be of guidance.

Almost any carrier substance may be employed. It is not necessary to use nitrocellulose lacquers, other films are suitable, whether the film forming material is a resin, at gum, a protein such as zein or casein, aoetyl cellulose, or

inorganic colloid such as bentonitic clays or the like. Generally, the hectograph mass should not be applied until the bonding film is well dried. Even traces of some lacquer solvents may interfere with the bonding.

Agitation or turbulence in the hectograph 1 mass, after application to the backing assists in forming a good bond.

A controlling factor of the binding qualities w is the time of contact between the backing and the hectograph mass, before the latter congeals.

Since theother factors may be varied so widely without departing from the invention, it is impossible to give any specific range for the time of contact. However, it is easy to determine the time of contact necessary for each set of conditions, by the following simple test: hectograph mass is poured onto the backing material carry-- 1 ing a bonding film of this invention. The backing material is kept at a temperature above the melting point of the mass for a certaintime and is then allowed to cool. The next day one can readily ascertain, by trying to pull oi! the film ofhectograph mass, whether or not this film adheres to the backing, or bonds." If it does not bond, the test is repeated allowing a longer time of contact between the-backing and the hectograph mass in themelted state; increasing .the

time of contact in melted state until bond means any organic acid or salt which dissociates in water to form an acid, or similar acid or acid forming substances which does not have the effect of rendering gelatin insoluble and which may be used in preparing a reversible colloidal suspension in water of the gelatin. So far as is known all non-tanning acidic organic substances are operable, although some, as has been heretofore pointed out, give better results than others.

While there have been shown and described certain embodiments of the invention, it is to be understood that it is capable of many modifications. Changes, therefore, may be made without departing from the spirit and scope of the invention as described in the appended claims, in which it is the intention to claim all novelty inherent in the invention as broadly as possible.

in view of the prior art.

I claim:

1. In a hectograph blanket comprising a gelabeing bonded together by a bond comprising an organic non-tanning acidic substance in which the sole acid forming radical is COOR where R is a hydrogen or metal.

3. A hectograph blanket having a copy mass and a backing, the copy mass and backing being bonded together by a bond comprising a cellulose derivative and an organic non-tanning acidic substance selected from the group consisting of carboxylic acids and salts thereof which dissociate in water to form the corresponding carboxylic acid.

4. A hectograph blanket comprising a gelatinous copy mass, a backing and an intermediate bonding layer comprising a cellulose derivaive and a carboxylic acid.

5. A hectograph blanket comprising a gelatinous copy mass, a backing and an intermediate bonding layer comprising a cellulose derivative and a salt of a carboxylic acid which dissociates in water to form the corresponding acid. 1

6. A hectograph blanket comprising a gelatinous copy mass, a backing and an intermediate bonding layer comprising a cellulose derivative and an alkali metal salt of naphthenic acid.

7. A hectograph blanket comprising a gelatinous copy mass, a backing and an intermediate bonding layer comprising a cellulose derivative and a naphthenic acid.

8. A hectograph blanket comprising a copy mass, a web base coated on the side remote from the copy mass with a relatively non-adhesive composition, and secured to the copy mass a metal.

ROBERT C. BOUR. 

